Noise Trade: Alive and Well?

Upon speculation of the attractiveness of Rio Tinto as a takeover target surfaced throughout the market, investors leapt into action forcing the share price up 5.22% to $91.38 by close of trade. Further speculation identifying the most likely bidder as BHP Billiton due to possible synergies instigated a 3.14% increase of its share price to $31.56. Both contributed to the S&P/ASX200 reaching an all time record of 6329.4 by end of trade 7th May.

Speculation continued across the next 2 days of trade prompting an ASX Price Query issuing to Rio Tinto for clarification about the speculated BHP takeover. Rio Tinto Company Secretary, Stephen Consedine confirmed by end of trade on the 9th of May that they were unaware of any BHP takeover offer sparking a 3.79% fall in the Rio Tinto share price the following day.

The overwhelming run on BHP and RIO shares across these few days could arguably be described as noise trading. But as both share prices currently sit at approximately 5% (RIO) and 1% (BHP) above their original share prices prior to speculation on the 7th of May, an interesting question arises. What percentage of the current share price represents an increase in value and what percentage if any represents noise trade?

I think this notion can quite readily be applied to the Australian resource and mining industry as a whole. With a notable trend line of approximately 20% share price growth for the Metals and Mining industry from November until now, does the Australian resource boom truly warrant this?